The present invention relates to binary computing operations, and more particularly to a method and apparatus for binary computing which employs an optically implemented Boolean AND and OR gate computing elements using non-linear organic polymers and photovoltaic/piezoelectric optical interfaces.
The parallel and high-speed features of optical systems can be used to fabricate general-purpose optical computers. Much research has been done on the optical realization of parallel processors for multiplication and addition. A parallel two-dimensional multiplication occurs when a two-dimensional spatially modulated light beam is passed through a two-dimensional transparency. Certain two-dimensional spatial light modulators can also produce an output that is the difference between two successive two-dimensional inputs or contains only the moving objects within a two-dimensional input scene. The addition of two two-dimensional data planes occurs if two spatially modulated beams are incident on a detector array simultaneously or sequentially. Various number representations have been used (such as residue arithmetic) to design efficient parallel optical and numerical computers.
The most attractive class of general-purpose optical computers is presently optical linear algebra processors. These systems perform matrix-vector operations and similar linear algebra algorithms, often in a systolic form. A typical system consists of a linear array of input point modulators (for example, laser diodes), each of which is imaged through a different spatial region of an acoustooptic cell. The Fourier transform of the light distribution leaving the cell is formed on a linear output detector array. If the elements of N input vectors are fed simultaneously at time t to the acoustooptic cell, each vector on a different frequency f, then the transmittance of the cell will be N vectors (that is, a matrix A). If the input point modulators are fed in parallel with the elements of another vector x, then the product of the input vector and the N vectors in the cell is formed, and each vector inner product is produced (by the Fourier-transform lens) on a separate output detector. Thus, the system performs N vector inner products or a matrix-vector multiplication in parallel. With various frequency, time, and space encoding techniques, different electrical postprocessing, and various feedback configurations, all of the major linear algebra operations required in modern signal processing can be achieved on this one system. Use of multichannel acoustooptic cells and related architectures can increase the processing capacity of the system and allow optical processing of data to the accuracy possible on digital computers.